Here’s cautionary lesson about the hype around hybrid and all-electric automobiles: A respected nonprofit group dedicated to energy efficiency just released its list of “greenest” cars among the 2011 class and seven of the top 13 rely on piston-driven “conventional” engines. In fact, the top performer on the list is the Honda Civic GX, which runs on compressed national gas. The heavily advertised Chevy Volt only ranked #13. No diesels made the list.

In a news release, ACEEE vehicle analyst Shruti Vaidyanathan says, “We’re seeing an increasing number of highly efficient gasoline options from both foreign and domestic automakers along with the first electric vehicles. Ford introduced the Fiesta this year and Chevrolet debuted the Cruze, both of which do exceedingly well in our ratings.”

Here are the ratings:

Honda Civic GX (compressed natural gas)

Nissan Leaf (electric)

Smart Fortwo Cabriolet/Coupe (gasoline)

Toyota Prius (hybrid)

Honda Civic Hybrid

Honda Insight (hybrid)

Ford Fiesta SFE (gasoline)

Chevrolet Cruze Eco (gasoline)

Hyundai Elantra (gasoline)

Mini Cooper (gasoline)

Toyota Yaris (gasoline)

Mazda 2 (gasoline)

Chevrolet Volt (hybrid)

As one can imagine, the Volt’s marketing managers are none too happy. A story from CNNMoney.com reports that GM is disparaging the ACEEE’s list and ranking system:

“I find it kind of laughable,” said GM spokesman Rob Peterson when told of ranking and the rational behind it. Peterson objected to the idea that the Volt’s weight counted so heavily against the Volt. “It’s one group’s interpretation of a measurement of ‘green’,” he said.

I think if will be a fairly long time before any of these technologies establishes a dominating position. To a certain extent, a variety of technologies will be required for a long time in certain applications, regardless of the potential, because of other economies and externalities (speed, distance, location), but its nice to see the “green” bar is being raised by not-to-be-ignore amounts each year. Whether it is occurring by revolutionary amounts — I’m thinking here about what is going on in other countries — remains to be seen.